Absorption or adsorption refrigerating apparatus



y 1943- N. ERLAND AF KLEEN 2,323,902 ABSORPTION OR ADSORPTION REFRIGERATING APPARATUS Original Filed July 16, 1957 INVENTOR. JWZI'fl/f/l/id rg fflem BY 6). gg f Patented July 13, 1943 ABSORPTION OR ABSORPTION REFRIGER- AT-ING APPARATUS Nils Erland af Kleen, Stockholm, Sweden Original application July 16, 1937, Serial No. 154,090. Divided and this application April 16, 1941, Serial No..388,763. In Great Britain July 2 Claims.

This invention relates to new and useful improvements .in absorption or adsorption refrigerating apparatus wherein the refrigerant circulates through a closed .system formed by .a plurality of interconnected elements including a combined generator and absorber containing :dry salts or other materials capable of absorbingor adsorbing a refrigerant in gaseous form during the absorbing periods and of giving up such refrigerant during the generating periods, the present application being a division of my co-pending application, Serial No. 154,090, :filed July 16, 1937, now Patent No. 2,274,680, covering Absorption and adsorption refrigerating apparatus. For convenience of'reference, the use of :the terms absorption and absorber in the followingde- .scription :and claims is intended to include also adsorption and adsorber,respectively. Similarly .the use of the expression dry salts iSJiI'ltended to mean any materials capable of ,absorbing gaseous refrigerant.

In apparatus of the type above mentioned, the boiler absorber contains a certain quantity of dry salts capable of absorbing a predetermined quantity of refrigerant and, upon the application of heat to the boiler, refrigerant is driven out, passes through a condenser where it is liquefied and the condensate is delivered to an evaporating system. The heat supplied to the boiler is usually controlled by a thermostat arrangement which operates to shut off the heat when the boiler temperature reaches a predetermined point. However, due to mechanical failure, the thermostat arrangement sometimes becomes inoperative to shut off the heat when the boiler temperature reaches the predetermined point with the result that the boiler absorber becomes heated to extremely high temperatures, creating a serious fire hazard.

It is therefore the primary object of the present invention to overcome the above noted disadvantages and to prevent overheating of the boiler in the event the thermostat becomes inoperative to shut off the heat.

Usually in the normal operation of an absorption refrigerating apparatus only a portion of the refrigerant circulates through the system, that is, during the generating period, less than the entire quantity of refrigerant absorbed by the dry salts is driven out and a like amount is reabsorbed during the absorbing period. Consequently, if the thermostat fails to shut off the supply of heat, more refrigerant is driven out and it is another object of the present invention to utilize the excess refrigerant over and above that normally circulating through the refrigerating system, to take up the excess heat supplied to the boiler and thereby prevent overheating of the latter.

With the above and other objects in view, which will appear as the description proceeds, my invention resides in the novel features hereinafter more clearly set forth in the following description and claims, reference being had to the accompanying drawing which illustrates diagrammatically by way of example, an absorption refrigerating system embodying the present invention.

In the drawing, I0 represents generally a boiler absorber in the form of a cylindrical shell H in which is arranged .a series of annular trays I2 containing dry salts 13. A flue l4 extends longitudinally through the central portion of the .shell for the purpose of heating the boiler absorber by any suitable heating element, such for example as a gas burner I5 arranged in the bottom of said flue. The refrigerant vapors generated during the heating period pass upwardly through an outlet pipe IE to an air-cooled condenser H where the vapors are condensed, and the condensate is delivered to an evaporating system shown in the form of a liquid accumulator or liquid collecting vessel I8 and evaporating coils Hi. When the boiler temperature has reached a predetermined point, the supply of heat is cut off any suitable thermostat means (not shown), and the liquid refrigerant collected in the evaporating system will evaporate to produce cold and return to the boiler absorber to be reabsorbed by the dry salts. The quantity of refrigerant driven out by the boiler absorber and delivered to the evaporating system during the generating period occupies a certain volume in the latter and has been designated by reference character 20, which represents the liquid level in the collecting vessel l8.

The thermostat is usually set to operate at a boiler temperature such that less than the total quantity of refrigerant initially charged to the system and absorbed by the dry salts, is driven out. Consequently, in the event the thermostat fails to shut off the heat, more refrigerant will be driven out. This excess refrigerant delivered to the evaporating system overflows into a downwardly extending conduit 2| arranged above the normal liquid level 20 and is returned to the boiler absorber Ill, being preferably vaporized prior to entering the boiler by passing through a coil portion 22 of the conduit 2| surrounding the heating flue l4.

Thus, part of the heat supplied by burner I is utilized to vaporize the excess refrigerant overflowing from the evaporating system and overheating of the boiler is thereby prevented. In other words, the vigorous circulation of the excess refrigerant through the boiler absorber I0, outlet pipe 16, condenser l1, evaporating system and overflow conduit 2| dissipates the heat at a high rate so that the boiler is not dangerously overheated.

From the foregoing it is believed that the construction, operation and advantages of the invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claims.

What I claim is:

1. Absorption refrigerating apparatus embodying a combined generating and absorbing element containing dry salts, a condensing element, an evaporating element, and conduit means connecting said elements together to form a closed system for the circulation of a refrigerant, means for supplying a predetermined amount of heat to said combined generating and absorbing element for the generation of refrigerant vapors, the quantity of refrigerant generated by the said predetermined amount of heat being less than the total quantity of refrigerant initially charged to the system and absorbed by the dry salts, and a conduit connected to said evaporating element for the overflow of surplus liquid refrigerant delivered to said evaporating element by an excess supply of heat to said combinedv generating and absorbing element, said conduit extending downwardly from said evaporating element and being connected to the bottom of said combined generating and absorbing element, said conduit having a portion of length intermediate said evaporating element and said combined generating and absorbing element disposed between said heat supplying means and said combined generating and absorbing element and arranged in direct heat transfer relation with said heat supplying means, whereby the surplus liquid refrigerant is vaporized and the excess supply of heat is dissipated to prevent overheating of said combined generating and absorbing element.

2. Refrigerating apparatus of the intermittent absorption type operating with solid absorbent material and embodying a combined generating and absorbing element, a condensing element and an evaporating element coupled together to form a closed system for the circulation of a refrigerant, means for supplying a predetermined amount of heat to said combined generating and absorbing element for the generation of refrigerant vapors, the quantity of refrigerant generated by said predetermined amount of heat being less than the total quantity of refrigerant initially charged to the system and absorbed by the absorbent material, and conduit means connected at one end to said evaporating element for the overflow of surplus liquid refrigerant delivered to said evaporating element by an excess supply of heat to said combined generating and absorbing element, the other end of said conduit means being in fluid communication with said combined generating and absorbing element, said conduit means having a portion of length intermediate its ends disposed between said heat-supplying means and said combined generating and absorbing element and in direct heat transfer relation with said heat supply means to vaporize the surplus liquid refrigerant flowing therethrough and take up the excess supply of heat whereby to prevent overheating of said combined generating and absorbing element.

NILS ERLAND AF KLEEN. 

